Mutant Gene Possible Cause of Sciatica

Researchers believe that mutations in a specific gene may be a cause of sciatica — a common and painful disorder caused by deterioration of discs in the lower back leading to compression of the sciatic nerve.

Identifying the mutation may lead to new therapies for patients suffering from back pain, explained senior author Dr. Leena Ala-Kokko of the University of Oulu, Finland, and MCP Hahnemann University in Philadelphia, Pennsylvania.

The team’s report, published in the July 16th issue of the journal Science, notes that poor disc alignment has been linked to malfunctioning collagen IX, one of a group of collagen compounds involved in vertebral development. Ala-Kokko’s team speculated that mutations in the COL9A2 gene — which helps direct collagen IX production — might play a role in poor alignment and related sciatica. To test this theory, they screened 157 sciatica patients and 174 healthy ‘controls’ for the presence of mutant COL9A2.

The result? Six of the subjects with sciatica carried mutant COL9A2, compared with none of the healthy controls.

The investigators then examined the incidence of mutant COL9A2 in the family members of four of the six sciatica subjects. They report that “all family members who had inherited the (mutant gene) had intervertebral disc disease.”

Sciatica probably has many causes, according to the authors, and not all individuals with sciatica will carry the mutant COL9A2 gene. But they estimate that the mutation may be responsible for at least 10% of cases in the Finnish population.